Little Miss was first seen in The Legend of Thunder!. When the Miracle Crystal, a device created by Team Rocket's Professor Sebastian that can attract and manipulate all nearby electric energy, started to create large thunder clouds, Little Miss wandered off to discover what was causing the strange weather. When Marina and Jimmy followed her, they discovered that Attila and Hun were trying to capture Raikou. At this point, Little Miss battled Attila's Skarmory and Hun's Steelix. She used her Perish Song attack, which successfully distracted the Pokémon long enough for Jimmy's Beedrill to damage the Miracle Crystal's machine.
Later on, Little Miss fought off Attila and Hun's Pokémon while Typhlosion and Meganium attempted to break through the force field trapping Raikou to free him from Attila and Hun.